The Irish LGBT group Lavender & Green Alliance would be allowed to participate under its own banner in the March 17 event, according to parade organizers.

They will join Out@NBCUniversal, a gay organization linked to the media outlet that was the first to break the barrier.

“With the decision, we cross a historic threshold and our members will proudly march up Fifth Avenue with our banner,” said Brendan Fay, founder and chair of the Queens-based Lavender & Green Alliance.

He also said the decision “sends a positive message across the Irish cultural landscape.”

The group’s application had been rejected every year since 1994. Previously, parade organizers said gay people could march but without banners or signs disclosing their sexual identities.

Mayor de Blasio, along with other top elected officials, have refused to march because of the exclusion.